Rolling piston rotary compressors include a cast metal cylinder forming a bore in which an eccentrically mounted roller rotates. A spring loaded blade or vane located in a slot in the cylinder block contacts the surface of the roller. As the roller is advanced around the cylinder bore, the blade reciprocates. An inlet port is located on one side of the blade to allow gas to enter an intake or suction chamber between the blade, the rotating roller and the cylinder. A discharge port is located on the opposite side of the blade to discharge compressed gas from a high pressure or compression chamber as the roller rotates. A compressor of this type is shown, for example, in U.S. Pat. No. 4,629,403.
In manufacturing a rolling piston rotary compressor, the cylinder block is cast from a metal such as iron or an aluminum alloy. After casting, the bore and the vane slot are finished by machining. It is necessary for obtaining a very close tolerance between the reciprocating blade or vane and the vane slot in the cylinder block to prevent loss of efficiency and loss of lubricating oil. Accordingly, in assembling the compressor, the width of the finished vane slot is accurately measured and a blade having a dimension for providing a desired tolerance is selected. This necessitates the high costs of either machining the blade to the desired dimensions after finishing and measuring the vane slot width of inventorying blades of different known dimensions and selecting a blade having the correct dimension for the finished slot.